Driving apparatus for washing machine

ABSTRACT

A driving apparatus for a washing machine is disclosed which includes a dual-motor type motor. The driving apparatus includes a tub which contains washing water, and receives a drum such that the drum is rotatable, a dual rotor which includes an outer motor including magnets supported by an inner peripheral surface of the outer rotor, the inner rotor arranged inside the outer rotor, the inner rotor including magnets supported by an outer peripheral surface of the inner rotator, a bearing housing which is formed at a rear wall of the tub in accordance with an insert molding method such that the bearing housing is integral with the tub, the bearing housing rotatably supporting a drum shaft connecting the drum and the dual rotor, a motor mounting bracket which is mounted to the rear wall of the tub, and a stator which includes a core arranged such that opposite surfaces of the core face the magnets of the outer rotor and the magnets of the inner rotor, respectively, an insulator made of an insulating material, the insulator enclosing the core, coils wound around the insulator, a molded member formed in accordance with an insert molding method to enclose the insulator and the coils such that the molded member is integral with the insulator and the coils while allowing the opposite surfaces of the core to be exposed, and a coupling member extending from the molded member, the coupling portion being mounted to the rear wall of the tub via the motor mounting bracket.

TECHNICAL FIELD

The present invention relates to a washing machine, and moreparticularly, to a driving apparatus for a washing machine wherein tworotors, which constitute a dual rotor, are arranged at opposite sides ofa stator, respectively, to achieve all enhancement in torque.

BACKGROUND ART

Generally, a washing machine performs a washing operation usingfrictional forces generated between laundry and wash water contained ina drum rotated by a drive force from a motor, and the function of adetergent dissolved in the wash water. The drum is a washing tub inwhich wash water and laundry are contained. The drum is applicable towashing machines of any types, namely, irrespective of a drum type or apulsator type.

Meanwhile, the driving system of the washing machine uses an indirectpower transmission system in which the driving force of the motor isindirectly transmitted to the drum via a belt wound between a motorpulley and a drum pulley, or a direct power transmission system in whichthe driving force of the motor is directly transmitted to the drum.

The indirect power transmission system, in which the driving force ofthe motor is indirectly transmitted to the drum via the belt woundbetween the motor pulley and the drum pulley without being directlytransmitted to the drum, has problems of loss of energy and great noisegenerated during the transmission of driving force. Taking intoconsideration such problems, use of washing machines using adirectly-connected motor has increased.

FIG. 1 is a sectional view illustrating a structure of a conventionaldrum washing machine.

As shown in FIG. 1, a tub 2 is disposed in a cabinet 1. A drum 3 iscentrally disposed in the tub 2 such that the drum 3 is rotatable.

A motor, which includes a rotor 5 and a stator 6, is arranged at therear of the tub 2. The stator 6 is fixedly mounted to a rear wall of thetub 2. The rotor 5 surrounds the stator 6, and is connected to the drum3 by a drum shaft 4 extending through the tub 2. Although not shown,magnets are arranged along an inner circumferential surface of the rotor5 such that opposite polarities are alternately arranged.

A door 7 is mounted to a front side of the cabinet 1. A gasket 8 isarranged between the door 7 and the tub 2. A suspension spring 9 a isarranged between the inner surface of the cabinet 1 at the top of thecabinet 1 and the outer surface of the tub 2 at the top of the tub 2, inorder to support the tub 2. A friction damper 9 b is arranged betweenthe inner surface of the cabinet 1 at the bottom of the cabinet 1 andthe outer surface of the tub 2 at the bottom of the tub 2, in order toattenuate vibrations generated at the tub 2 during a spin-dryingoperation.

A tub support (not shown), which is made of metal, is interposed betweenthe rear wall of the tub 2 and the stator 6, in order to support theweight of the stator 6 and to maintain the concentricity of the stator6. The tub support has a structure approximately similar to the profileof the rear wall of the tub 2. The tub support is fixed to the rear wallof the tub 2.

When the stator 6 receives electric power, it functions as anelectromagnet. In this state, the rotor 5 is rotated by a rotatingmagnetic field formed between the stator 6 and the magnets of the rotor5. The rotating force of the rotor 5 is transmitted to the drum via thedrum shaft 4.

Recently-developed washing machines have a tendency to provide a largecapacity. Due to such a tendency, the motor, which is used to rotate adrum in such a washing machine, must have increased power. For thisreason, the sizes of the rotor and stator in the motor must beincreased, thereby incurring a problem of a great increase in the sizeand weight of the motor.

In order to solve this problem, the applicant proposed a washing machineincluding a dual-rotor type motor, as disclosed in Korean PatentLaid-open Publication No. 2001-0097204 (published on Nov. 8, 2001). Inthe disclosed dual-rotor type motor, coils are wound on a stator at theinside and outside of the stator, respectively. An inner rotor and anouter rotor are arranged at the inside and outside of the stator,respectively, such that a predetermined gap is defined between eachrotor and the stator. By virtue of such a dual rotor structure, themotor can have increased power.

However, such a dual-rotor type motor must be more firmly mounted to awashing machine or the like, correspondingly to the increased-powerthereof.

DISCLOSURE OF INVENTION Technical Problem

An object of the present invention devised to solve the above-mentionedproblems lies in providing a driving apparatus for a washing machinewhich has a structure enabling the driving apparatus to be stably fixedto a tub of the washing machine, and to generate high power.

Technical Solution

In accordance with one aspect of the present invention, the presentinvention provides a driving apparatus for a washing machine comprising:a tub which contains washing water, and receives a drum such that thedrum is rotatable; a dual rotor which includes an outer rotor includingmagnets supported by an inner peripheral surface of the outer rotor, andan inner rotor arranged inside the outer rotor, the inner rotorincluding magnets supported by an outer peripheral surface of the innerrotor; a bearing housing which is formed at a rear wall of the tub inaccordance with an insert molding method such that the bearing housingis integral with the tub, the bearing housing rotatably supporting adrum shaft connecting the drum and the dual rotor; a motor mountingbracket which is mounted to the rear wall of the tub; and a stator whichis mounted to the rear wall of the tub via the motor mounting bracketsuch that the stator is arranged between the outer rotor and the innerrotor, the stator generating magnetic energy using electrical energysupplied from an external of the stator, to rotate the dual rotor.

The stator may include a core arranged such that opposite surfaces ofthe core face the magnets of the outer rotor and the magnets of theinner rotor, respectively, an insulator made of an insulating material,the insulator enclosing the core, coils wound around the insulator, amolded member formed in accordance with an insert molding method toenclose the insulator and the coils such that the molded member isintegral with the insulator and the coils while allowing the oppositesurfaces of the core to be exposed, and a coupling member extending fromthe molded member, the coupling portion being mounted to the rear smallof the tub via the motor mounting bracket.

Alternatively, the stator may include a core arranged such that oppositesurfaces of the core face the magnets of the outer rotor and the magnetsof the inner rotor, respectively, an insulator enclosing the core, coilswound around the insulator, and a coupling member extending from themolded member, the coupling member being mounted to the rear wall of thetub via the motor mounting bracket.

In accordance with another aspect, the present invention provides adriving apparatus for a washing machine comprising: a tub which containswashing water, and receives a drum such that the drum is rotatable; adual rotor which includes an outer rotor including magnets supported byan inner peripheral surface of the outer rotor, and an inner rotorarranged inside the outer rotor, the inner rotor including magnetssupported by an outer peripheral surface of the inner rotor; a bearinghousing which is formed at a rear wall of the tub in accordance with aninsert molding method such that the bearing housing is integral with thetub, the bearing housing rotatably supporting a drum shaft connectingthe drum and the dual rotor; a motor mounting bracket which is mountedto the rear wall of the tub; and a stator which is mounted to the motormounting bracket such that the stator is arranged between the outerrotor and the inner rotor, the stator generating magnetic energy usingelectrical energy supplied from an external of the stator, to rotate thedual rotor.

In accordance with another aspect, the present invention provides adriving apparatus for a washing machine comprising: a tub which containswashing water, and receives a drum such that the drum is rotatable, thetub including a plurality of bracket mounting bosses formed at a rearwall of the tub, and a plurality of stator mounting bosses formed at therear wall of the tub; a dual rotor which includes an outer rotorincluding magnets supported by an inner peripheral surface of the outerrotor, and an inner rotor arranged inside the outer rotor, the innerrotor including magnets supported by an outer peripheral surface of theinner rotor; a bearing housing which is formed at a rear wall of the tubin accordance with an insert molding method such that the bearinghousing is integral with the tub, the bearing housing rotatablysupporting a drum shaft connecting the drum and the dual rotor; a motormounting bracket which is mounted to the rear wall of the tub, and isformed with a plurality of outer coupling holes respectivelycorresponding to the bracket mounting bosses such that bolts arefastened through the outer coupling holes and the corresponding bracketmounting bosses, and a plurality of inner coupling holes respectivelycorresponding to the stator mounting bosses such that bolts are fastenedthrough the inner coupling holes and the stator mounting bosses; and astator which includes a core arranged such that opposite surfaces of thecore face the magnets of the outer rotor and the magnets of the innerrotor, respectively, an insulator made of an insulating material, theinsulator enclosing the core, coils wound around the insulator, a moldedmember formed in accordance with an insert molding method to enclose theinsulator and the coils such that the molded member is integral with theinsulator and the coils while allowing the opposite surfaces of the coreto be exposed, and a coupling member extending from the molded member,the coupling portion being mounted to the rear wall of the tub via themotor mounting bracket.

In accordance with another aspect, the present invention provides adriving apparatus for a washing machine comprising: a tub which containswashing water, and receives a drum such that the drum is rotatable, thetub including a plurality of bracket mounting bosses formed at a rearwall of the tub; a dual rotor which includes an outer rotor includingmagnets supported by an inner peripheral surface of the outer rotor, andan inner rotor arranged inside the outer rotor, the inner rotorincluding magnets supported by an outer peripheral surface of the innerrotor; a bearing housing which is formed at a rear wall of the tub inaccordance with an insert molding method such that the bearing housingis integral with the tub, the bearing housing rotatably supporting adrum shaft connecting the drum and the dual rotor; a motor mountingbracket which is mounted to the rear wall of the tub, and is formed witha plurality of outer coupling holes respectively corresponding to thebracket mounting bosses such that bolts are fastened through the outercoupling holes and the corresponding bracket mounting bosses, and aplurality of inner coupling holes arranged inside the outer couplingholes; and a stator which includes a core arranged such that oppositesurfaces of the core face the magnets of the outer rotor and the magnetsof the inner rotor, respectively, an insulator made of an insulatingmaterial, the insulator enclosing the core, coils wound around theinsulator, a molded member formed in accordance with an insert moldingmethod to enclose the insulator and the coils such that the moldedmember is integral with the insulator and the coils while allowing theopposite surfaces of the core to be exposed, and a coupling memberextending from the molded member, the coupling portion being mounted tothe motor mounting bracket.

In accordance with another aspect, the present invention provides adriving apparatus for a washing machine comprising: a tub which containswashing water, and receives a drum such that the drum is rotatable, thetub including a plurality of bracket mounting bosses formed at a rearwall of the tub; a dual rotor which includes an outer rotor includingmagnets supported by an inner peripheral surface of the outer rotor, andan inner rotor arranged inside the outer rotor, the inner rotorincluding magnets supported by an outer peripheral surface of the innerrotor; a bearing housing which is formed at a rear wall of the tub inaccordance with an insert molding method such that the bearing housingis integral with the tub, the bearing housing rotatably supporting adrum shaft connecting the drum and the dual rotor; a motor mountingbracket which is mounted to the rear wall of the tub, and is formed witha plurality of outer coupling holes respectively corresponding to thebracket mounting bosses such that bolts are fastened through the outercoupling holes and the corresponding bracket mounting bosses, and aplurality of inner coupling holes arranged inside the outer couplingholes; and a stator which includes a core arranged such that oppositesurfaces of the core face the magnets of the outer rotor and the magnetsof the inner rotor, respectively, an insulator enclosing the core, coilswound around the insulator, and a coupling member extending from theinsulator, the coupling portion being mounted to the rear wall of thetub via the motor mounting bracket.

In accordance with still another aspect, the present invention providesa driving apparatus for a washing machine comprising: a tub whichcontains washing water, and receives a drum such that the drum isrotatable, the tub including a plurality of bracket mounting bossesformed at a rear wall of the tub; a dual rotor which includes an outerrotor including magnets supported by an inner peripheral surface of theouter rotor, and an inner rotor arranged inside the outer rotor, theinner rotor including magnets supported by an outer peripheral surfaceof the inner rotor; a bearing housing which is formed at a rear wall ofthe tub in accordance with an insert molding method such that thebearing housing is integral with the tub, the bearing housing rotatablysupporting a drum shaft connecting the drum and the dual rotor; a motormounting bracket which is mounted to the rear wall of the tub, and isformed with a plurality of outer coupling holes respectivelycorresponding to the bracket mounting bosses such that bolts arefastened through the outer coupling holes and the corresponding bracketmounting bosses, and a plurality of inner coupling holes arranged insidethe outer coupling holes; and a stator which includes a core arrangedsuch that opposite surfaces of the core face the magnets of the outerrotor and the magnets of the inner rotor, respectively, an insulatorenclosing the core, coils wound around the insulator, and a couplingmember extending from the insulator, the coupling portion being mountedto the motor mounting bracket.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention, illustrate embodiments of the inventionand together with the description serve to explain the principle of theinvention.

In the drawings:

FIG. 1 is a longitudinal sectional view schematically illustrating astructure of a drum washing machine to which a conventional outer rotortype motor is applied;

FIG. 2 is a longitudinal sectional view schematically illustrating astructure of a driving apparatus which includes a dual-rotor type motorin accordance with an embodiment of the present invention;

FIG. 3 is an exploded perspective view illustrating the dual-rotor typemotor shown in FIG. 2;

FIG. 4 is a rear view of a tub, illustrating a mounting structure of thedriving apparatus shown in FIG. 2;

FIG. 5 is a front view illustrating a motor mounting bracket in thedriving apparatus shown in FIG. 2;

FIG. 6 is a longitudinal sectional view illustrating a driving apparatusfor a washing machine according to another embodiment of the presentinvention;

FIG. 7 is a longitudinal sectional view illustrating a driving apparatusfor a washing machine according to another embodiment of the presentinvention;

FIG. 8 is a front view illustrating a motor mounting bracket in thedriving apparatus shown in FIG. 7; and

FIG. 9 is a perspective view illustrating a structure of an auxiliarybracket in the driving apparatus shown in FIG. 7.

BEST MODE FOR CARRYING OUT THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention associated with a driving apparatus for a washingmachine, examples of which are illustrated in the accompanying drawings.

Referring to FIGS. 2 and 3, a driving apparatus for a washing machineaccording to a preferred embodiment of the present invention isillustrated. As shown in FIGS. 2 and 3, a drum shaft 4 is mounted to acentral portion of the rear wall of a drum 3 (FIG. 1) such that the drumshaft 4 extends rearwards. A bearing housing H is insert-molded at acentral portion of the rear wall of a tub 2 (FIG. 1) such that thebearing housing H is integral with the tub 2. Inner and outer bearings Bare fitted in the bearing housing H.

A motor, which is adapted to rotate the drum shaft 4, is mounted to therear wall of the tub 2. The motor is a dual-rotor type motor whichincludes an outer rotor 10, an inner rotor 20, and a stator 30. Thestator 30 is fixed to the rear wall of the tub 2. The outer rotor 10 andinner rotor 20 are arranged at opposite sides of the stator 30,respectively, such that gaps are defined between the outer rotor 10 andthe inner peripheral surface of the stator 30 and between the innerrotor 20 and the outer peripheral surface of the stator 30,respectively.

A busing 40, which is made of an insulating resin material, is mountedto a central portion of the outer rotor 10. The drum shaft 4 is fixedlymounted to the busing 40. The mounting of the busing 40 to the centralportion of the outer rotor 10 is achieved by fasteners such as bolts 42.Of course, the busing 40 may be formed integrally with the outer rotor10, using an insert molding method.

The busing 40 is centrally provided with a hole in which the drum shaft4 is fitted. Serrations 41 are formed at the inner surface of the hole.The serrations 41 are engaged with serrations 4 a formed at the outersurface of the drum shaft 4.

A plurality of magnets 11 are arranged along an inner peripheral surfaceof the outer rotor 10 such that N and S-poles are alternately arranged.A plurality of magnets 21 are arranged along an outer peripheral surfaceof the outer rotor 10 such that N and S-poles are alternately arranged.The magnets 21 face the magnets 11. Preferably, the outer rotor 10 andinner rotor 20 are coupled to each other at lower portions thereofcontacting each other, using caulks 23 and caulking holes formed inaccordance with a pressing and caulking process.

Although the outer rotor 10 and inner rotor 20 may be injection-molded,it is preferred that the outer rotor 10 and inner rotor 20 be made of ametal material, so as to function as back yokes. Of course, where theouter rotor 10 and inner rotor 20 are injection-molded using a resinmaterial, back yokes made of metal must be attached to the outer rotor10 and inner rotor 20, to establish magnetic paths.

Meanwhile, the stator 30 includes a plurality of core segments 31 whichare separate from one another, an insulator 32 which encloses the core31, and is made of an insulating resin material, coils 34 which arewound around the insulator 32, and a molded member 33 which is moldedusing an insert molding method to enclose the insulator 32 and coils 34.The insulator 32 may be dispensed with, so long as enamel is coated overthe outer surfaces of the coils 34, to ensure desired electricalinsulation.

The molded member 33 is also provided with a coupling portion 35 forcoupling the molded member 33 to the tub 2. The coupling portion 35extends radially inwardly from an inner peripheral surface of one end ofthe molded member 33. A plurality of coupling holes 35 a and a pluralityof positioning holes 35 b are formed through the coupling portion 35.

Of course, the coupling portion 35 may extend radially outwardly fromthe molded member 33.

Preferably, the coupling portion 35 is formed in accordance with aninsert molding method such that the coupling portion 35 is integral withthe molded member 33. However, the coupling portion 35 may be formedseparately from the molded member 33. In this case, the coupling portion35 is coupled to the molded member 33. In this case, the couplingportion 35 may be made of a metal or resin material identical to ordifferent from that of the molded member.

A reinforcing member is provided at the outer surface of the moldedmember 33, in order to increase the strength of the molded member 33.Preferably, the reinforcing member comprises a plurality of reinforcingribs 33 c. Also, reinforcing ribs 35 c are preferably formed at an innercorner where the molded member 33 meets the coupling portion 35.Provided, rotation of the inner rotor 20 should not be interfered withby the reinforcing ribs 35 c.

Of course, in place of the reinforcing ribs 33 c and 35 c, a reinforcingbracket (not shown), which is made of metal and has an annular shape,may be attached to the inner or outer surface of the molded member 33,in order to increase the strength of the molded member 33.

A Hall sensor 38 is arranged at one side of the stator 30, to detect therotating speed of the rotors. The Hall sensor 38 has sensor terminalswhich are fitted in holes 33 d formed in the top of the stator 30 at oneside of the stator 30, to detect the rotating speed of the rotors. Aconnector 37 is formed at the molded member 33 such that they areintegral, in order to supply electric power to each coil 34 of thestator 30.

As shown in FIGS. 2, 4, and 5, the stator 30 is fixedly mounted to therear wall of the tub 2 via a motor mounting bracket 50.

In detail, a plurality of bracket mounting bosses 2 a are formed on therear wall of the tub 2 at a position radially spaced apart from the axisof the tub 2 such that the bracket mounting bosses 2 a arecircumferentially arranged while being circumferentially spaced apartfrom one another by a predetermined distance. Also, a plurality ofuniformly-spaced stator mounting bosses 2 b are formed on the rear wallof the tub 2 inside the bracket mounting bosses 2 a, to mount the stator30 to the rear wall of the tub 2.

A plurality of positioning protrusions 2 c are formed at the rear wallof the tub 2. The positioning protrusions 2 c determine the positions ofthe motor mounting bracket 50 and stator 30 such that the motor mountingbracket 50 and stator 30 are concentrically arranged. Positioning holes54 are formed through the motor mounting bracket 50 at positionscorresponding to the positioning protrusions 2 c, respectively. Thepositions of the positioning holes 54 also correspond to the positioningholes 35 b of the stator 30, respectively.

Each positioning protrusion 2 c preferably has a conical end so that thepositioning protrusion 2 c can be easily inserted into the correspondingpositioning hole 35 b of the stator 30.

Each positioning hole 35 b of the stator 30 preferably has a shape and asize identical to those of each positioning protrusion 2 c such that thepositioning protrusion 2 c is tightly fitted in the positioning hole 35b without any gap after the insertion thereof.

That is, the portion of the positioning groove 35 b, in which a bodyportion of the positioning protrusion 2 c is received, preferably has acylindrical shape having a uniform diameter corresponding to that of thebody portion, and the portion of the positioning groove 35 b, in whichthe conical end portion of the positioning protrusion 2 c is received,preferably has a conical shape corresponding to that of the guideportion and having a gradually-reduced diameter. Preferably, eachpositioning groove 35 b of the stator 30 has a diameter smaller thanthat of the associated coupling hole 35 a.

Reversely to the above-described case, the positioning protrusions maybe formed at the stator 30, and the positioning holes may be formed atthe motor mounting bracket 50 and tub 2.

As shown in FIGS. 4 and 5, the motor mounting bracket 50 is made of anapproximately-circular metal plate, and is provided with a plurality ofuniformly-spaced inner coupling holes 53 and a plurality ofuniformly-spaced outer coupling holes 52 at positions corresponding tothe bracket mounting bosses 2 a and stator mounting bosses 2 b of thetub 2, respectively

When the positioning protrusions 2 c of the tub 2 are inserted into thepositioning holes 54 of the motor mounting bracket 50, respectively, theouter coupling holes 52 of the motor mounting bracket 50 are accuratelyaligned with the bracket mounting bosses 2 a of the tub 2, respectively.In this state, the motor mounting bracket 50 can be mounted to the rearwall of the tub 2 by fastening bolts 58 through the outer coupling holes52 and bracket mounting bosses 2 a.

Thereafter, the stator 30 is coupled to the rear wall of themotor-mounting bracket 50 such that the positioning protrusions 2 c areinserted into the positioning holes 35 b of the stator 30, respectively.In this state, the stator 30 can be firmly mounted to the rear wall ofthe tub 2 by fastening bolts 39 through the coupling holes 35 a of thestator 30, the inner coupling holes 53 of the motor mounting bracket 50,and the stator mounting bosses 2 b of the tub 2.

Of course, differently from the above-described embodiment, the mountingof the stator 30 to the motor mounting bracket 50 can be achieved byfastening the bolts 39 only through the inner coupling holes 53 of themotor mounting bracket 50 and the coupling holes 35 a of the stator 30.That is, the stator 30 can be directly mounted to the rear surface ofthe motor mounting bracket 50 without being mounted to the tub 2.

Meanwhile, where the stator 30 is mounted to the rear wall of the tub 2via the motor mounting bracket 50, as described above, there areadvantages in that it is possible to increase the rigidity of the tub 2,which is made of a plastic mold, and to firmly fix the stator 30 to thetub 2.

The end of the drum shaft 4 is coupled to the busing 40 mounted to theouter rotor 10 after the mounting of the stator 30 to the rear wall ofthe tub 2, as described above. Thus, the mounting of the motor iscompleted.

FIG. 6 is a sectional view illustrating a structure of a drivingapparatus for a washing machine according to another embodiment of thepresent invention.

As shown in FIG. 6, the basic configuration of the driving apparatusaccording to this embodiment is identical to that of the above-describedembodiment.

Provided, the driving apparatus of this embodiment is different fromthat of the above-described embodiment in that no separate molded memberis provided at a stator 130 constituting a motor, and a coupling portion135 extends directly from an insulator 132 arranged around a core 131.

That is, as shown in FIG. 6, in the stator 130, the coupling portion 135extends radially inwardly from an end of the insulator 132 adjacent tothe tub 2. A plurality of uniformly-spaced coupling holes 135 a and aplurality of uniformly-spaced positioning holes 135 b are formed throughthe coupling portion 135. Of course, differently from the illustratedcase, the coupling portion 135 may extend radially outwardly from theinsulator 132.

The coupling portion 135 is preferably formed integrally with theinsulator 132. However, the coupling portion 135 may be fabricated inthe form of a metal frame, separately from the insulator 132. In thiscase, the coupling portion 135 is coupled to the insulator 132.

Since the mounting of the coupling portion 135 of the insulator 132 canbe achieved in the same manner as in the above-described embodiment, nodetailed description thereof will be given.

FIGS. 7 to 9 illustrate a driving apparatus for a washing machineaccording to another embodiment of the present invention.

The basic configuration of the driving apparatus according to thisembodiment is identical to that of the first embodiment.

Provided, the driving apparatus of this embodiment is different fromthat of the first embodiment in terms of the structure for mounting thestator 30 to the tub 2.

In the driving apparatus of the above-described embodiment, the portionof the tub 2 corresponding to a region where the connector 37 (FIG. 3)and hall sensor 38 (FIG. 3) are arranged may be slightly inwardlydepressed because the connector 37 is formed at the surface of thestator 30 contacting the tub 2. In this case, the rigidity of the tub 2may be degraded at the depressed portion.

In this embodiment, accordingly, an auxiliary bracket 260 having apredetermined thickness is interposed between the motor mounting bracket250 and the stator 30, to form a space between the rear wall of the tub2 and the stator 30, and thus, to prevent the tub 2 from being formedwith a depressed portion.

A plurality of positioning pins 265 are formed at one surface of theauxiliary bracket 260 such that the positioning pins 265 arecircumferentially arranged while being circumferentially spaced apartfrom one another by a predetermined distance. The positioning pins 265position the auxiliary bracket 260 to be concentric to the motormounting bracket 250 when the auxiliary bracket 260 is mounted to themotor mounting bracket 250. A plurality of bolt coupling holes 262 areformed through the auxiliary bracket 260 at positions corresponding tothe coupling holes 35 a of the stator 30 and the stator mounting bosses2 b of the tub 2, respectively, such that the bolt coupling holes 262are circumferentially arranged while being circumferentially spacedapart from one another by a predetermined distance.

In order to concentrically position the auxiliary bracket 260 and stator30, a plurality of positioning pins (not shown) are preferably protrudedfrom the stator 30. Also, positioning holes 264 are preferably formed atthe auxiliary bracket 260 such that the positioning holes 264 arecircumferentially arranged while being circumferentially spaced apartfrom one another by a predetermined distance.

The auxiliary bracket 260 is preferably made of an aluminum alloy.

The driving apparatus for a washing machine according to the presentinvention has advantages as follows.

First, in the driving apparatus of the present invention, inner andouter rotors are arranged at the inside and outside of a stator,respectively. Accordingly, it is possible to greatly increase the powerof the driving apparatus, namely, a motor, without a considerableincrease in the size and weight of the motor.

Second, in accordance with the present invention, the core and insulatorof the stator are supported by a molded member. Accordingly, it ispossible to easily implement a structure for coupling the stator to thewashing machine.

Third, where the molded member encloses the core, insulator, and coilsof the stator, the stator can have superior waterproofness. Accordingly,where the motor of the present invention is applied to an apparatususing water, for example, a washing machine, there is little or nopossibility that a short circuit occurs in the stator due to watercontacting the stator. Accordingly, an enhancement in durability isachieved.

Fourth, since the stator is mounted to the rear all of the tub via themotor mounting bracket, the mounting of the stator to the tub can befirmly and easily achieved.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

INDUSTRIAL APPLICABILITY

The present invention is applicable to a driving apparatus for rotatinga drum of a washing machine.

1. A driving apparatus for a washing machine comprising: a tub whichcontains washing water, and receives a drum such that the drum isrotatable; a dual rotor which includes an outer rotor including magnetssupported by an inner peripheral surface of the outer rotor, and aninner rotor arranged inside the outer rotor, the inner rotor includingmagnets supported by an outer peripheral surface of the inner rotor; abearing housing which is formed at a rear wall of the tub in accordancewith an insert molding method such that the bearing housing is integralwith the tub, the bearing housing rotatably supporting a drum shaftconnecting the drum and the dual rotor; a motor mounting bracket whichis mounted to the rear wall of the tub; and a stator which is mounted tothe rear wall of the tub via the motor mounting bracket such that thestator is arranged between the outer rotor and the inner rotor, thestator generating magnetic energy using electrical energy supplied froman external of the stator, to rotate the dual rotor.
 2. The drivingapparatus according to claim 1, wherein the stator includes: a corearranged such that opposite surfaces of the core face the magnets of theouter rotor and the magnets of the inner rotor, respectively; aninsulator made of an insulating material, the insulator enclosing thecore; coils wound around the insulator; a molded member formed inaccordance with an insert molding method to enclose the insulator andthe coils such that the molded member is integral with the insulator andthe coils while allowing the opposite surfaces of the core to beexposed; and a coupling member extending from the molded member, thecoupling portion being mounted to the rear wall of the tub via the motormounting bracket.
 3. The driving apparatus according to claim 1, whereinthe stator includes: a core arranged such that opposite surfaces of thecore face the magnets of the outer rotor and the magnets of the innerrotor, respectively; an insulator enclosing the core; coils wound aroundthe insulator; and a coupling member extending from the molded member,the coupling member being mounted to the rear wall of the tub via themotor mounting bracket.
 4. The driving apparatus according to claim 1,further comprising: a plurality of bracket mounting bosses formed at therear wall of the tub; and a plurality of outer coupling holes formedthrough the motor mounting bracket such that the outer coupling holescorrespond to the bracket mounting bosses, respectively, whereby themotor mounting bracket is mounted to the tub when bolts are fastenedthrough the bracket mounting bosses of the tub and the outer couplingholes of the motor mounting bracket.
 5. The driving apparatus accordingto claim 4, further comprising: a plurality of stator mounting bossesformed at the rear wall of the tub; a plurality of inner coupling holesformed through the motor mounting bracket such that the inner couplingholes correspond to the stator mounting bosses, respectively; and aplurality of coupling holes formed at the stator such that the couplingholes correspond to the stator mounting bosses, respectively, andcorrespond to the inner coupling holes, respectively, whereby the statoris mounted to the tub when bolts are fastened through the statormounting bosses, the inner coupling holes, and the coupling holes, inthis order.
 6. The driving apparatus according to claim 1, furthercomprising: a positioning unit which determines positions of the motormounting bracket and the stator to be fixed with respect to the tub suchthat the stator is concentrically coupled to the drum shaft.
 7. Themotor according to claim 6, wherein the positioning unit includes: atleast one positioning protrusion protruded from the tub; a firstpositioning hole formed through the motor mounting bracket such that thefirst positioning hole receives the positioning protrusion; and a secondpositioning hole formed through the stator such that the secondpositioning hole receives the positioning protrusion.
 8. The drivingapparatus according to claim 6, wherein the positioning unit includes atleast one first positioning hole formed at the tub; a second positioninghole formed through the motor mounting bracket slash that the secondpositioning hole corresponds to the first positioning hole; and apositioning protrusion protruded from the stator such that thepositioning protrusion extends through the first and second positioningholes.
 9. The driving apparatus according to claim 5, furthercomprising: an auxiliary bracket which is interposed between the statorand the motor mounting bracket, and is formed with a plurality of boltcoupling bosses respectively corresponding to the stator mountingbosses, the inner coupling holes, and the coupling holes.
 10. Thedriving apparatus according to claim 9, wherein the auxiliary brackethas an annular shape.
 11. The driving apparatus according to claim 9,wherein the auxiliary bracket is made of an aluminum material.
 12. Thedriving apparatus according to claim 9, further comprising: apositioning unit which determines positions of the auxiliary bracket andthe stator to be fixed with respect to the tub such that the stator isconcentrically coupled to the drum shaft.
 13. The driving apparatusaccording to claim 12, wherein the positioning unit includes at leastone first positioning hole formed at the tub; a first positioning pinprotruded from the auxiliary bracket toward the tub such that the firstpositioning pin is inserted into the first positioning hole; a secondpositioning hole formed through the auxiliary bracket; and a secondpositioning pin protruded from the stator toward the auxiliary bracketsuch that the second positioning pin is inserted into the secondpositioning hole.
 14. The driving apparatus according to claim 2,wherein the molded member of the stator is provided with a reinforcingmember for increasing a strength of the molded member.
 15. The drivingapparatus according to claim 14, wherein the reinforcing membercomprises a plurality of reinforcing ribs formed at an outer surface ofthe molded member such that the reinforcing ribs are integral with themolded member.
 16. A driving apparatus for a washing machine comprising:a tub which contains washing water, and receives a drum such that thedrum is rotatable; a dual rotor which includes an outer rotor includingmagnets supported by an inner peripheral surface of the outer rotor, andan inner rotor arranged inside the outer rotor, the inner rotorincluding magnets supported by an outer peripheral surface of the innerrotor; a bearing housing which is formed at a rear wall of the tub inaccordance with an insert molding method such that the bearing housingis integral with the tub, the bearing housing rotatably supporting adrum shaft connecting the drum and the dual rotor; a motor mountingbracket which is mounted to the rear wall of the tub; and a stator whichis mounted to the motor mounting bracket such that the stator isarranged between the outer rotor and the inner rotor, the statorgenerating magnetic energy using electrical energy supplied from anexternal of the stator, to rotate the dual rotor.
 17. The drivingapparatus according to claim 16, wherein the stator includes: a corearranged such that opposite surfaces of the core face the magnets of theouter rotor and die magnets of the inner rotor, respectively; aninsulator made of an insulating material, the insulator enclosing thecore; coils wound around the insulator; a molded member formed inaccordance with an insert molding method to enclose the insulator andthe coils such that the molded member is integral with the insulator andthe coils while allowing the opposite surfaces of the core to beexposed; and a coupling member extending from the molded member, thecoupling portion being mounted to the rear wall of the tub via the motormounting bracket.
 18. The driving apparatus according to claim 16,wherein the stator includes: a core arranged such that opposite surfacesof the core face the magnets of the outer rotor and the magnets of theinner rotor, respectively; an insulator enclosing the core; coils woundaround the insulator; and a coupling member extending from the moldedmember, the coupling member being mounted to the rear wall of the tubvia the motor mounting bracket.
 19. The driving apparatus according toclaim 16, further comprising: a plurality of bracket mounting bossesformed at the rear wall of the tub; and a plurality of outer couplingholes formed through the motor mounting bracket such that the outercoupling holes correspond to the bracket mounting bosses, respectively,whereby the motor mounting bracket is mounted to the tub when bolts arefastened through the bracket mounting bosses of the tub and the outercoupling holes of the motor mounting bracket.
 20. The driving apparatusaccording to claim 19, further comprising: a plurality of inner couplingholes formed through the motor mounting bracket; and a plurality ofcoupling holes formed at the coupling member of the stator such that thecoupling holes correspond to the inner coupling holes, respectively,whereby the stator is mounted to the motor mounting bracket when boltsare fastened through the inner coupling holes and the coupling holes, inthis order.
 21. The driving apparatus according to claim 20, furthercomprising: an auxiliary bracket which is interposed between thecoupling member of the stator and the motor mounting bracket, and isformed with a plurality of bolt coupling bosses respectivelycorresponding to the inner coupling holes of the motor mounting bracketand the coupling holes of the stator.
 22. The driving apparatusaccording to claim 17, wherein the molded member of the stator isprovided with a reinforcing member for increasing a strength of themolded member.
 23. The driving apparatus according to claim 22, whereinthe reinforcing member comprises a plurality of reinforcing ribs formedat an outer surface of the molded member such that the reinforcing ribsare integral with the molded member.
 24. A driving apparatus for awashing machine comprising: a tub which contains washing water, andreceives a drum such that the darn is rotatable, the tub including aplurality of bracket mounting bosses formed at a rear wall of the tub,and a plurality of stator mounting bosses formed at the rear wall of thetub; a dual rotor which includes an outer rotor including magnetssupported by an inner peripheral surface of the outer rotor, and aninner rotor arranged inside the outer rotor, the inner rotor includingmagnets supported by an outer peripheral surface of the inner rotor; abearing housing which is formed at a rear wall of the tub in accordancewith an insert molding method such that the bearing housing is integralwith the tub, the bearing housing rotatably supporting a drum shaftconnecting the drum and the dual rotor; a motor mounting bracket whichis mounted to the rear wall of the tub, and is formed with a pluralityof outer coupling holes respectively corresponding to the bracketmounting bosses such that bolts are fastened through the outer couplingholes and the corresponding bracket mounting bosses, and a plurality ofinner coupling holes respectively corresponding to the stator mountingbosses such that bolts are fastened through the inner coupling holes andthe stator mounting bosses; and a stator which includes a core arrangedsuch that opposite surfaces of the core face the magnets of the outerrotor and the magnets of the inner rotor, respectively, an insulatormade of an insulating material, the insulator enclosing the core, coilswound around the insulator, a molded member formed in accordance with aninsert molding method to enclose the insulator and the coils such thatthe molded member is integral with the insulator and the coils whileallowing the opposite surfaces of the core to be exposed, and a couplingmember extending from the molded member, the coupling portion beingmounted to the rear wall of the tub via the motor mounting bracket. 25.The driving apparatus according to claim 24, further comprising: anauxiliary bracket which is interposed between the coupling member of thestator and the motor mounting bracket, and is formed with a plurality ofbolt coupling bosses respectively corresponding to the inner couplingholes of the motor mounting bracket and the coupling holes of thestator.
 26. A driving apparatus for a washing machine comprising: a tubwhich contains washing water, and receives a drum such that the drum isrotatable, the tub including a plurality of bracket mounting bossesformed at a rear wall of the tub; a dual rotor which includes an outerrotor including magnets supported by an inner peripheral surface of theouter rotor, and an inner rotor arranged inside the outer rotor, theinner rotor including magnets supported by an outer peripheral surfaceof the inner rotor; a bearing housing which is formed at a rear wall ofthe tub in accordance with an insert molding method such that thebearing housing is integral with the tub, the bearing housing rotatablysupporting a drum shaft connecting the drum and the dual rotor; a motormounting bracket which is mounted to the rear wall of the tub, and isformed with a plurality of outer coupling holes respectivelycorresponding to the bracket mounting bosses such that bolts arefastened through the outer coupling holes and the corresponding bracketmounting bosses, and a plurality of inner coupling holes arranged insidethe outer coupling holes; and a stator which includes a core arrangedsuch that opposite surfaces of the core face the magnets of the outerrotor and the magnets of the inner rotor, respectively, an insulatormade of an insulating material, the insulator enclosing the core, coilswound around the insulator, a molded member formed in accordance with aninsert molding method to enclose the insulator and the coils such thatthe molded member is integral with the insulator and the coils whileallowing the opposite surfaces of the core to be exposed, and a couplingmember extending from the molded member, the coupling portion beingmounted to the motor mounting bracket.
 27. The driving apparatusaccording to claim 26, further comprising: an auxiliary bracket which isinterposed between the coupling member of the stator and the motormounting bracket, and is formed with a plurality of bolt coupling bossesrespectively corresponding to the inner coupling holes of the motormounting bracket and the coupling holes of the stator.
 28. A drivingapparatus for a washing machine comprising: a tub which contains washingwater, and receives a drum such that the drum is rotatable, the tubincluding a plurality of bracket mounting bosses formed at a rear wallof the tub; a dual rotor which includes an outer rotor including magnetssupported by an inner peripheral surface of the outer rotor, and aninner rotor arranged inside the outer rotor, the inner rotor includingmagnets supported by an outer peripheral surface of the inner rotor; abearing housing which is formed at a rear wall of the tub in accordancewith an insert molding method such that the bearing housing is integralwith the rub, the bearing housing rotatably supporting a drum shaftconnecting the drum and the dual rotor; a motor mounting bracket whichis mounted to the rear wall of the tub, and is formed with a pluralityof outer coupling holes respectively corresponding to the bracketmounting bosses such that bolts are fastened through the outer couplingholes and the corresponding bracket mounting bosses, and a plurality ofinner coupling holes arranged inside the outer coupling holes; and astator which includes a core arranged such that opposite surfaces of thecore face the magnets of the outer rotor and the magnets of the innerrotor, respectively, an insulator enclosing the core, coils wound aroundthe insulator, and a coupling member extending from the insulator, thecoupling portion being mounted to the rear wall of the tub via the motormounting bracket.
 29. The driving apparatus according to claim 28,further comprising: an auxiliary bracket which is interposed between thecoupling member of the stator and the motor mounting bracket, and isformed with a plurality of bolt coupling bosses respectivelycorresponding to the inner coupling holes of the motor mounting bracketand the coupling holes of the stator.
 30. A driving apparatus for awashing machine comprising: a tub which contains washing water, andreceives a drum such that the drum is rotatable, the tub including aplurality of bracket mounting bosses formed at a rear wall of the tub; adual rotor which includes an outer rotor including magnets supported byan inner peripheral surface of the outer rotor, and an inner rotorarranged inside the outer rotor, the inner rotor including magnetssupported by an outer peripheral surface of the inner rotor; a bearinghousing which is formed at a rear wall of the tub in accordance with aninsert molding method such that the bearing housing is integral with thetub, the bearing housing rotatably supporting a drum shaft connectingthe drum and the dual rotor; a motor mounting bracket which is mountedto the rear wall of the tub, and is formed with a plurality of outercoupling holes respectively corresponding to the bracket mounting bossessuch that bolts are fastened through the outer coupling holes and thecorresponding bracket mounting bosses, and a plurality of inner couplingholes arranged inside the outer coupling holes; and a stator whichincludes a core arranged such that opposite surfaces of the core facethe magnets of the outer rotor and the magnets of the inner rotor,respectively, an insulator enclosing the core, coils wound around theinsulator, and a coupling member extending from the insulator, thecoupling portion being mounted to the motor mounting bracket.
 31. Thedriving apparatus according to claim 30, further comprising: anauxiliary bracket which is interposed between the coupling member of thestator and the motor mounting bracket, and is formed with a plurality ofbolt coupling bosses respectively corresponding to the inner couplingholes of the motor mounting bracket and the coupling holes of thestator.